• Journal of the Korean Mathematical Society
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• v.36 no.2
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• pp.431-445
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• 1999

A digraph T is called a local tournament if for every vertex x of T, the set of in-neighbors as well as the set of out-neighbors of in-neighbors of x induce tournaments. Let x and y be two vertices of a 3-connected and arc-3-cyclic local tournament T with y x. We investigate the structure of T such that T contains no (x,y)-path of length k for some k with 3 k V(T) -1. Our result generalized those of [2] and [5] for tournaments.

• Electronics and Telecommunications Trends
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• v.35 no.5
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• pp.57-68
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• 2020

This paper reviews the recent trends in optical access technologies and their future directions. As the number of hyper-connected, ultra-low-latency, and hyper-realistic services increases, the wireless path has become shorter and the optical access network has become deeply penetrated into the end user. The optical access network continues to evolve through endless innovation via high-speed, ultra-low-latency, and abstraction/virtualization technologies.

• Bulletin of the Korean Mathematical Society
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• v.31 no.1
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• pp.61-72
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• 1994

Every irreducible block-finite orthomodular lattice is simple [9] and every irreducible orthomodular alttice such that no proper p-ideal of L contains infinitely many commutators is simple [5]. Every finite (height) OML L which does not belong to the varitety generated by MO2 has one of the OML MO3, 2$^{3}$.2$^{2}$, D$_{16}$ OMLHOUSE as the homomorpyhic image of a subalgebra of L [3]. In this paper, we extend these results.s.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.2043-2052
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• 1994

This paper proposes a new parallel ASIC architecture for real-time image processing to reduce inter-processing element (inter-PE) communication overhead, called a Sliding Memory Plane (SliM) Image Processor. The Slim Image Processor consists of $3\times3$ processing elements (PEs) connected by a mesh topology. With easy scalability due to the topology. a set of SliM Image Processors can form a mesh-connected SIMD parallel architecture. called the SliM Array Processor. The idea of sliding means that all pixels are slided into all neighboring PEs without interrupting PEs and without a coprocessor or a DMA controller. Since the inter-PE communication and computation occur simultaneously. the inter-PE communication overhead, significant disadvantage of existing machines greatly diminishes. Two I/O planes provide a buffering capability and reduce the date I/O overhead. In addition, using the by-passing path provides eight-way connectivity even with four links. with these salient features. SliM shows a significant performance improvement. This paper presents architectures of a PE and the SliM Image Processor, and describes the design of an instruction set.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.176-186
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• 2008

As determined single coaxial cable for the interface between satellite and ground station in COMS RF compatibility test, RF supporting unit was required to allow signals in different frequency-band to be exchanged in the single coaxial cable. In addition, the path loss between satellite and ground station in normal operation should be simulated through two RF supporting units connected to the ends of single coaxial cable. As an effort to design RF supporting unit, level diagram was firstly conducted on the basis of measured data for each element. From the level diagram, it was found that single coaxial cable connected with two RF supporting units properly represented the path loss between satellite and ground station After RF supporting unit was integrated on aluminum plate, it was tested that input signal level at each test cap linked with MODCS and TC&R was tunable within the required dynamic range. RF supporting unit, now completely integrated, will be applied in the upcoming COMS RF compatibility test.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.7-14
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• 2022

Sensor Registry System (SRS) has been devised for maintaining semantic interoperability of data on heterogeneous sensor networks. SRS measures the connectability of the mobile device to ambient sensors based on positions and only provides metadata of sensors that may be successfully connected. The step of identifying the ambient sensors which can be successfully connected is called sensor filtering. Improving the performance of sensor filtering is one of the core issues of SRS research. In reality, GPS sometimes shows the wrong position and thus leads to failed sensor filtering. Therefore, this paper proposes a new sensor filtering strategy using geographical embedding and neural network-based path prediction. This paper also evaluates the service provision rate with the Monte Carlo approach. The empirical study shows that the proposed method can compensate for position abnormalities and is an effective model for sensor filtering in SRS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2367-2372
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• 2009

Recently, Many studies have been progressing to path-finding adapted dynamic information on the Terminal Based Navigation System(TBNS). The algorithms proposed are based on $A^*$ algorithm. Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost. Path-finding with an abstract graph which expresses real road network as a simple graph is proposed for reducing dependency of heuristic and exploring cost. In this paper, two abstract graph that are different method of construction, Homogeneous Node merging($AG^H$) and Connected Node Merging($AG^C$), are implemented. In result of evaluation of performance, $AG^C$ has better performance than $AG^H$ at construction cost and the number of node access but $AG^C$ has worse performance than AGH at exploring cost.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.7
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• pp.697-703
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• 2012

In this study, duodenogastric reflux has been investigated according to pyloroplasty and the path of the gastric tube in esophageal reconstruction. The paths of the gastric graft (front and rear paths) were determined from the CT images of ten patients, and the gastric tube model was constructed using an RP technique. The gastric tubes were connected to the pylorus models with and without pyloroplasty. Various distal pressures and pulse widths were applied, and the volume and maximum height of the refluxate were measured. The results show that the volume and height of the refluxate increase with the distal pressure, and the front path leads to a smaller volume and lesser height of the refluxate than the rear path if pyloroplasty is conduced. The volume of the refluxate is markedly increased by a larger pulse width, but its effect on the maximum height depends on whether pyloroplasty is conducted.

• Progress in Superconductivity and Cryogenics
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• v.6 no.2
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• pp.20-24
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• 2004

Bi-2223 wire, the first-generation high temperature superconducting (HTS) wire, was successfully commercialized and various electrical machinery and equipment are actively being developed in many countries. Because its critical current is too small to realize the lossless conducting part of electric power system with a HTS wire, multi-HTS paths are used to enlarge the critical current of HTS system. Though the resistance generated in HTS wire by transport current is very small, the difference of it in multi-path is the additional reason which causes the non-uniform current sharing in multi-HTS path except the well known reason, the difference of inductance between each path. In this paper, experimental research on current sharing of multi-strand and multi-stacked HTS wire was implemented. The whole critical current of multi-HTS paths is not equal to sum of critical current of each path because of non-uniform current sharing occurred in this paths. It was verified experimentally that Bi-2223 wires have different resistance generated by same transport current even if they was manufactured in same progress of work. Current sharing phenomenon was affected by difference of resistance and self and mutual inductance.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.295-302
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• 2014

This study demonstrates a double-path CDI as an alternative of advanced wastewater treatment process. While the CDI typically consists of many pairs of electrodes connected in parallel, the new double-path CDI is designed to have series flow path by dividing the module into two stages. The CFD model showed that the double-path had uniform flow distribution with higher velocity and less dead zone compared with the single-path. However, the double-path was predicted to have higher pressure drop(0.7 bar) compared the single-path (0.4 bar). From the unit cell test, the highest TDS removal efficiencies of single- and double-path were up to 88% and 91%, respectively. The rate of increase in pressure drop with an increase of flow rate was higher in double-path than single-path. At 70 mL/min of flow rate, the pressure drop of double-path was 1.67 bar, which was two times higher than single-path. When the electrode spacing was increased from 100 to $200{\mu}m$, the pressure drop of double-path decreased from 1.67 to 0.87 bar, while there was little difference in TDS removal. When proto type double-path CDI was operated using sewage water, TDS, $NH_4{^+}$-N, $NO_3{^-}$-N and $PO_4{^{3-}}$-P removal efficiencies were up to 78%, 50%, 93% and 50%, respectively.